Time Sequence Control Circuit

1. A time sequence control circuit for controlling a first voltage received by a power supply receiving terminal of a motherboard of a computer greater than a preset voltage before a signal control terminal on the motherboard receives a second voltage during turning on the computer, the control circuit comprising: a control circuit connected to the power supply receiving terminal to receive the first voltage; a delay circuit connected to the control circuit; and a power conversion circuit connected between the delay circuit and the signal control terminal, to convert the first voltage into the second voltage; wherein the control circuit comprises first and second diodes, and first and second electronic switches, anodes of the first and second diodes are connected to the power supply receiving terminal, a cathode of the first diode is grounded via first and second resistors connected in series, a cathode of the second diode is connected to the delay circuit, a first terminal of the first electronic switch is connected to a node between the first and second resistors, a second terminal of the first electronic switch is grounded, a third terminal of the first electronic switch is connected to a first terminal of the second electronic switch, and is also connected to the power supply receiving terminal via a third resistor, a second terminal of the second electronic switch is grounded, a third terminal of the second electronic switch is connected to the delay circuit; when the computer is turned on, the first voltage increases to the preset voltage, the first terminal of the first electronic switch is at high level, the first electronic switch is turned on, the first terminal of the second electronic switch is at a low level, and the second electronic switch is turned off; and wherein when the computer is turned on, the power supply receiving terminal increases to the preset voltage, the control circuit is turned off, the power conversion circuit converts the first voltage into the second voltage and provides the second voltage to the signal control terminal after delaying for a period of time.

2. The control circuit of claim 1 , wherein the first and second electronic switches are npn bipolar junction transistors, and the first to third terminals of the first and second electronic switches are bases, emitters, and collectors of the npn bipolar junction transistors.

3. The control circuit of claim 1 , wherein the third terminal of the first electronic switch is connected to the node between the first and second resistors via a fourth resistor.

4. The control circuit of claim 1 , wherein the delay circuit comprises a fourth resistor and a capacitor, the fourth resistor is connected between the cathode of the second diode and the third terminal of the second electronic switch, and the capacitor is connected between the third terminal of the second electronic switch and ground.

5. The control circuit of claim 4 , wherein the power conversion circuit comprises third to sixth electronic switches, a first terminal of the third electronic switch is connected to the third terminal of the second electronic switch via a fifth resistor, a second terminal of the third electronic switch is grounded, a third terminal of the third electronic switch is connected to a first terminal of the fourth electronic switch, and is also connected to the power supply receiving terminal via a sixth resistor, a second terminal of the fourth electronic switch is grounded, a third terminal of the fourth electronic switch is connected to the signal control terminal, a first terminal of the fifth electronic switch is connected to the third terminal of the second electronic switch, a second terminal of the fifth electronic switch is grounded, a third terminal of the fifth electronic switch is connected to the power supply receiving terminal via a seventh resistor, and is also connected to a first terminal of the sixth electronic switch via an eighth resistor, a second terminal of the sixth electronic switch is connected to the power supply receiving terminal, a third terminal of the sixth electronic switch is grounded via a ninth and a tenth resistors, a node between the ninth and tenth resistors is connected to the signal control terminal; wherein when the computer is turned on, the first voltage increases to the preset voltage, the third and fifth electronic switches are turned on after delayed for a period of time by the delay circuit, the first terminals of the fourth and sixth electronic switches are at low level, the fourth electronic switch is turned off, the sixth electronic switch is turned on, and the signal control terminal receives the second voltage.

6. The control circuit of claim 5 , wherein the third and fifth electronic switches are re-channel metal oxide semiconductor field effect transistors (NMOSFETs), and the first to third terminals of the third and fifth electronic switches are gates, sources, and drains of the NMOSFETs, respectively.

7. The control circuit of claim 5 , wherein the fourth and sixth electronic switches are npn and pnp bipolar junction transistors, respectively, and the first to third terminals of the fourth and sixth electronic switches are bases, emitters, and collectors of the npn and pnp bipolar junction transistors, respectively.

8. The control circuit of claim 1 , wherein a maximum voltage of the first voltage is 3.3 volts.

9. The control circuit of claim 1 , wherein the preset voltage is 2.7 volts.